This invention relates to aircraft, and more particularly, to aircraft with VTOL technology.
Currently, there are three kinds of traditional VTOL technologies which get vertical lift from high-speed air flowing over upper surface of the aircraft. In the first one such as patent No: US201210068020, a fan independent of a main engine increases speed of low-temp air flowing over the upper surface of wing along the direction of the chord, thereby increasing vertical lift. In this way, this fan less efficiently increases the vertical lift; In the second one such as patent No: GB792993, a high-temp bypass duct directs high-temp air by a valve from a nozzle of a jet engine to flow radially over the upper surface of the aircraft, thereby generating vertical life. In this way, the high-temp bypass duct generates the vertical lift more efficiently than the first one but the upper surface of the aircraft might be burnt up; In the third one such as patent No: GB2469612, a low-temp bypass duct directs low-temp air, with a rotatable nozzle, from a low-temp duct of a turbofan engine to flow over the upper surface of the wing along the direction of the chord, thereby generating vertical lift. But another rotatable nozzle spouts high-temp air downwardly from a high-temp duct of a turbofan engine, thereby generating another vertical lift less efficiently. In this way, the low-temp bypass duct generates the vertical lift more efficiently than above ways but thin slot outlet of the low-temp bypass duct, set in the direction of the chord, enables a part of vertical lift to lose in the long low-temp bypass duct and the problem, how the high-temp air is directed to obtain more vertical lift from the upper surface of the aircraft but not burn up it, is not solved. Because of these limitations, VTOL is impossible for aircraft, and more particularly for large aircraft with thrust-to-weight ratio smaller than 0.1.